In industrial process installations, vortex flowmeters are used to measure fluid flow rates through piping systems. The vortex flowmeter includes an electronic transmitter and a vortex meter housing. The vortex meter housing carries the fluid flow and supports a bluff body in the fluid flow. The vortex meter housing is generally cylindrical and fits between flanges in the piping system.
Vortices are generated by fluid flow past the bluff. The occurrence of the vortices is generally proportional to fluid velocity. The vortex frequency is measured by the electronic transmitter and used to calculate a flowmeter output that indicates the flowrate.
A first type of vortex flowmeter (described below in connection with FIG. 1) includes additional sensors for sensing fluid temperature and pressure and is able to calculate mass flow from the vortex frequency, the temperature and the pressure. A second type of vortex flowmeter does not include pressure and temperature sensors and is not capable of calculating mass flow. The second type of vortex flowmeter is generally less costly than the first type of vortex flowmeter. The second type of vortex flowmeter is used primarily in applications where temperature is relatively constant or density is relatively independent of temperature such as liquid flows.
Manufacture of two different types of flowmeters in multiple lines sizes greatly increases the cost and complexity of manufacturing and inventorying vortex flowmeters.